Liquid substance supply device for vaporizing system, vaporizer, and vaporization performance appraisal method

ABSTRACT

In a liquid substance supply device, a three port two valve directional control valve is provided in a transfer line, and a substance container and the transfer line are connected together by a four port three valve directional control valve in such a way that the four port three valve directional control valve and the substance container can be removed from the transfer line as a unit. Furthermore, in a vaporizer, an orifice member is provided to surround the end portion of an internal conduit in which flows a mixture substance consisting of a gas and a liquid substance mixed therewith, and gas for atomization is spouted into a vaporization chamber through a gap defined between the internal conduit and the orifice member. Yet further, the temperature of a vaporization surface in the vaporization chamber can be controlled independently in correspondence with the nature of the liquid substance.

INCORPORATION BY REFERENCE

The disclosures of the following priority applications are hereinincorporated by reference:

Japanese Patent Application No. 2000-292757, filed Sep. 26, 2000;

Japanese Patent Application No. 2000-292758, filed Sep. 26, 2000;

Japanese Patent Application No. 2000-292759, filed Sep. 26, 2000;

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid substance supply device for avaporizing system which vaporizes a liquid substance such as a liquidorganometal or an organometal solution or the like, and also relates toa vaporizer and to a vaporization performance appraisal method.

2. Description of the Related Art

The MOCVD (Metal Organic Chemical Vapor Deposition) method is known asone thin film deposition method in semiconductor device manufacturingprocesses. In recent years this MOCVD method is rapidly coming intowidespread use, since the resulting film quality and the speed of filmdeposition and step coverage and so on are superior by comparison tospattering methods and the like. There are various methods of supplyingthe CVD gas which is used in MOCVD devices, such as the bubbling methodand the sublimation method. In recent years, the method of supplying aliquid substance that is a liquid organometal or an organometaldissolved in an organic solvent and vaporizing it directly before theCVD reactor has become recognized as an excellent method from the pointof view of controllability and stability. In such a vaporization method,a liquid substance is supplied to a vaporizer by a liquid substancesupply device, and, in the vaporizer, the liquid substance is sprayedfrom a nozzle into a vaporization chamber which is maintained at a hightemperature, and is thus vaporized.

However, the liquid substance which is used in such a MOCVD method caneasily undergo hydrolytic reactions, and there has been a danger thatits nature may change due to precipitates being formed in the liquid orthe like. Such generation of precipitates can easily lead to problemswith the operation of valves provided in the liquid supply lines, or theoccurrence of residues within the vaporizer or blockages due to theprecipitates or the like. As a result there have been the problems thatthe rate of flow may become less stable and consistent, and that, if theresidues form into particles which arrive at the CVD reactor, theconsistency of film deposition may be deteriorated.

In the past, a mass flow controller in which a mass flow meter and aflow amount control valve are combined together has generally beenemployed for controlling the rate of flow of a liquid substance. If athermal type mass flow meter is used as the mass flow meter, it caneasily be influenced by the ambient temperature, and accordingly it isnot desirable to locate such a meter in the vicinity of the vaporizerwhich attains high temperatures. On the other hand, from the point ofview of responsiveness of flow rate control, it is desirable to locatethe mass flow controller directly before the vaporizer. As a resultthere is the problem that, when determining the position in which such amass flow controller is to be disposed, one or the other of accuracy offlow control and responsiveness must be sacrificed, and accordinglyeither case causes insufficient installation condition.

Furthermore, when it is not possible to provide a sufficient supply ofheat energy to the liquid substance during vaporization, it can happenthat non-vaporized residues can be created and can cause blockages inthe supply conduits, and there is a danger that the residues can becomeparticulated and can arrived at the CVD reactor and can cause poor filmdeposition. Yet further, when vaporizing a mixture of a plurality ofcomponents, since the vaporization temperatures and the pyrolysis(thermal decomposition) temperature characteristics of the variouscomponents are different, it has been easy for residues to be generatedby non vaporization or by pyrolysis of some of the components.

Yet further, although it is necessary to appraise the vaporizationperformance under various conditions of vaporization in orderefficiently to implement vaporization while suppressing the generationof non vaporized residues, it is extremely difficult to perform suchappraisal due to the characteristics of the substances and so on, and upto the present no established appraisal method has been developed.

SUMMARY OF THE INVENTION

A primary objective of the present invention is to provide a liquidsubstance supply device which suppresses the generation of residues orbubbles, and with which the stability and controllability of liquidsubstance supply are good.

Another objective of the present invention is to provide a vaporizerwhich can reduce the generation of non vaporized residues and particles,and furthermore to provide a reliable vaporization performance appraisalmethod.

In order to achieve the above described objectives, in the liquidsubstance supply device according to the present invention, there isprovided a three port two valve directional control valve of unitarystructure, disposed at a branch point where a liquid substance transferline which supplies a liquid substance to a vaporizer branches intothree directions. This three port two valve directional control valvecomprises a first valve body, provided between a first conduit and asecond conduit, which performs an ON-OFF control of transfer of fluidbetween the first conduit and the second conduit, and a second valvebody, provided between the second conduit and a third conduit, whichperforms an ON-OFF control of transfer of fluid between the secondconduit and the third conduit, with the second conduit being providedbetween the first valve body and the second valve body.

Furthermore, according to another aspect of the liquid substance supplydevice according to the present invention, a four port three valvedirectional control valve of unitary structure is provided between theliquid substance transfer and the gas supply lines and the substancecontainer, and the substance container and the four port three valvedirectional control valve can be attached to and removed from the gassupply line and the liquid substance transfer line as one unit. Thisfour port three valve directional control valve comprises (a) a firstvalve body, provided between a first conduit and a second conduit, whichperforms an ON-OFF control of transfer of fluid between the firstconduit and the second conduit, (b) a second valve body, providedbetween the first conduit and a third conduit, which performs an ON-OFFcontrol of transfer of fluid between the first conduit and the thirdconduit, and (c) a third valve body, provided between the third conduitand a fourth conduit, which performs an ON-OFF control of transfer offluid between the third conduit and the fourth conduit; and the firstconduit is provided between the first valve body and the second valvebody, while the third conduit is provided between the second valve bodyand the third valve body. Moreover, the first conduit and the gas supplyline are connected together, the second conduit and a gas region of thesubstance container are connected together, the third conduit and theliquid substance transfer line are connected together, and the fourthconduit and a liquid region of the substance container are connectedtogether.

According to another aspect of the liquid substance supply deviceaccording to the present invention, the substance container whichcontains the liquid substance may comprise a casing to which gas fromthe gas supply line is supplied, and an inner bag which is flexible orbellows-shaped, is housed within the casing, and stores the liquidsubstance. When the gas is supplied to within the casing, the liquidsubstance in the inner bag is expelled from the substance containertowards the liquid substance transfer line. It is also possible toprovide to this liquid substance supply device a measurement means whichmeasures the amount of liquid substance in the inner bag, based uponvariation of the pressure of the gas supplied to the interior of thecasing.

Furthermore, according to another aspect of the liquid substance supplydevice according to the present invention, the substance container maycomprise a first bellows-shaped bag into which the liquid substance ischarged, and a second bellows-shaped bag which is connected to the firstbellows-shaped bag in series in the expansion and contraction directionof the first bellows-shaped bag, and which contracts the firstbellows-shaped bag by gas supply from the gas supply line, so as toexpel the liquid substance within the first bellows-shaped bag towardsthe liquid substance transfer line. An indication member is provided toa connection portion between the first bellows-shaped bag and the secondbellows-shaped bag and indicates the position of the connection portion.

There may also be provided a drain tank whose interior is evacuated to alow pressure state, which is connected via a valve to the liquidsubstance transfer line directly before the vaporizer, and whichreceives waste fluid from the liquid substance transfer line .

Furthermore, there may also be provided in the liquid substance transferline a detection device which detects the presence or absence of theliquid substance or the presence or absence of bubbles. A photoelectricsensor may be used for this detection device.

Yet further, there may be provided a thermal mass flow rate meter and aflow rate control valve which are separated from one another, with theflow rate meter being disposed on the side of the liquid substancetransfer line towards the substance container, and the flow rate controlvalve being disposed on the side of the liquid substance transfer linetowards the vaporizer. The flow rate control valve may also comprise acutoff mechanism which can cut off the supply of the liquid substance

One of PEEK (polyether ether ketone), PTFE (polytetrafluoroethylene), PI(polyimide), and PBI (polybenzimidiazole) may be used as the materialfor making a resin member which contacts the liquid substance, providedin the liquid substance transfer line.

In the liquid substance transfer line there may be provided a filterwhich comprise a plurality of layers of a first mesh made of stainlesssteel (SUS) which has a fine wire diameter and a plurality of layers ofa second mesh made of stainless steel (SUS) which has a coarse wirediameter. PTFE mesh may be employed instead of the stainless steel (SUS)mesh.

Moreover, in the vaporizer according to the present invention, there isprovided a transfer conduit from which a gas and liquid mixturesubstance is sprayed, which is made as a double conduit comprising aninternal conduit in which a liquid substance is transferred as agas/liquid two phase flow, and an external conduit into which theinternal conduit is inserted keeping a space and which transfers gas foratomization. And an end portion of the internal conduit is insertedkeeping a gap into an orifice member, and gas for atomization is spoutedinto the vaporization section through this gap.

Furthermore, at the tip of the atomization section there may be provideda nozzle ring having a vaporization surface, and the orifice member maybe disposed between the nozzle ring and the tip of the external conduitand may be made from PEEK (polyether ether ketone), and a seal membermade from PTFE (polytetrafluoroethylene) may be disposed between theorifice member and the tip of the external conduit. This orifice memberand seal member work to hinder the transfer of heat between the nozzlering and the external conduit, so that the liquid substance whichadheres to the vaporization surface can easily vaporize, and it ispossible to prevent the occurrence of residues of the liquid substanceupon the end portion of the atomization section. The nozzle ring may befixed to the vaporization section.

Yet further, the nozzle ring may comprise a first member which isengaged with the tip of the atomization section by screwing, and asecond member which is provided separately from the first member and issandwiched between the orifice member and the first member.

The internal conduit and the atomization section may be connected by agasket type seal coupling which employs a metal gasket. The atomizationsection is fixed to one of a pair of coupling members of this gaskettype seal coupling, while the internal conduit is fixed to the othercoupling member. The amount of projection of the internal conduit endportion from the orifice member can be adjusted by adjusting the amountof screwing in the axial direction of the gasket type seal coupling.

Furthermore, the vaporizer may comprise an atomization section whichsprays a gas/liquid mixture substance consisting of a mixture of aliquid substance which contains a liquid organometal or an organometalsolution and a carrier gas, from an end portion of a transfer conduit,and a vaporization section which vaporizes the sprayed liquid substance,with the liquid substance flowing through the transfer conduit in anannular spray flow state.

Yet further, in a vaporizer in which a liquid substance is sprayed intoa vaporization chamber which is kept at a high temperature and isvaporized, a vaporization surface, the temperature of which can becontrolled independently of the temperature of the vaporization chamber,may be provided within the vaporization chamber. Moreover, a pluralityof spray sections may be provided, and in this case each such spraysection should oppose a vaporization surface whose temperature can beindependently controlled.

It is also possible to form, in the vaporization chamber, a tubularchamber extending in the horizontal direction, with the liquid substancebeing sprayed in the vertically downwards direction into the tubularchamber against its inner wall surface. Furthermore, by coating thevaporization surface with a film of the same substance as the film whichis deposited by the CVD film deposition device, it is possible toprevent the occurrence of chemical reactions between the vaporizationsurface and the liquid substance.

Appraisal of the vaporization performance of the vaporizer is performedas follows. In detail, after a predetermined amount of the liquidsubstance has been sprayed into the vaporization chamber and has beenvaporized therein, the non-vaporized adherent material in thevaporization chamber is removed using an organic solvent, the amount ofthe liquid substance which is contained in the organic solvent which hasbeen used for this removal is measured, and the vaporization performanceis appraised based upon this contained liquid substance amount which hasbeen measured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a figure showing the general structure of a vaporizing system.

FIG. 2 is a figure showing the details of a liquid substance supplydevice.

FIG. 3 is a figure showing an external view of flow rate control valves9A through 9D.

FIG. 4 is a sectional view of a filter 18A.

FIG. 5 is a figure showing the stability of the flow rate through thefilter 18A.

FIG. 6 is a figure showing the open and closed states of the variousvalves during liquid substance supply.

FIG. 7 is a front elevation view of a three port two valve directionalcontrol valve assembly 15.

FIG. 8 is a view of the valve assembly 15 of FIG. 7 as seen in thedirection shown by the arrow A in FIG. 7.

FIG. 9 is a flow diagram for this three port two valve directionalcontrol valve assembly 15.

FIG. 10 is a sectional view of this valve assembly 15 taken in a planeshown by the arrows B—B in FIG. 8.

FIG. 11 is a sectional view of this valve assembly 15 taken in a planeshown by the arrows C—C in FIG. 10.

FIG. 12 is a plan view of a four port three valve directional controlvalve assembly 10.

FIG. 13 is a view of this valve assembly 10 as seen in the directionshown by the arrow D in FIG. 12.

FIG. 14 is a flow diagram for this four port three valve directionalcontrol valve assembly 10.

FIG. 15 is a sketch figure showing the structures within a body 101 ofthe four port three valve directional control valve assembly 10.

FIG. 16 is a figure showing the open and closed states of the valvesduring rinsing.

FIG. 17 is a figure showing the open and closed states of the valvesduring gas purging.

FIG. 18 is a figure showing the open and closed states of the valvesduring vacuum evacuation.

FIG. 19 is a figure showing the open and closed states of the valvesduring gas purging.

FIG. 20 is a figure showing the open and closed states of the valvesduring solvent rinsing.

FIG. 21 is a figure showing the open and closed states of the valvesduring fluid substitution.

FIG. 22 is a general figure showing an observation device 16.

FIG. 23 is a sectional view of a substance container 3A.

FIG. 24 is a sectional view showing a first variant embodiment of thissubstance container.

FIG. 25 is a sectional view showing a second variant embodiment of thissubstance container.

FIG. 26 is a sectional view showing a third variant embodiment of thissubstance container.

FIG. 27 is a sectional view of a vaporizer 2.

FIG. 28 is an enlarged view of a portion of a coupling 22.

FIG. 29 is a figure showing a first variant embodiment of a method ofconnecting a conduit 224 and an internal conduit 200 a.

FIG. 30 is a figure showing a second variant embodiment of a method ofconnecting the conduit 224 and the internal conduit 200 a.

FIG. 31 is a figure showing a third variant embodiment of a method ofconnecting the conduit 224 and the internal conduit 200 a.

FIG. 32 is an enlarged view showing the portion E of FIG. 27.

FIG. 33 is a enlarged view showing the portion F of FIG. 27.

FIG. 34 is a figure showing the temperature distribution in the axialdirection within the internal conduit 200 a.

FIG. 35 is a figure qualitatively showing the changes in the temperatureand the pressure of a liquid substance before and after vaporization.

FIG. 36 is a figure for explanation of the stability of atomization in avaporizer.

FIG. 37 is a sectional view showing a first variant embodiment of acooling rod 202.

FIG. 38 is a sectional view showing a second variant embodiment of thecooling rod 202.

FIG. 39 is a figure showing a first variant embodiment of a nozzle ring211.

FIG. 40 is a figure showing a second variant embodiment of the nozzlering 211.

FIG. 41 is a sectional view of another vaporizer 120.

FIG. 42 is a sectional view of the vaporizer 120 of FIG. 41 taken in aplane shown by the arrows G—G in FIG. 41.

FIG. 43 is a figure showing the relationship between the pyrolysistemperatures and the vaporization temperatures of liquid substances 4Athrough 4C, and the temperature of a vaporization surface.

FIG. 44 is a figure showing another vaporizer 40.

FIG. 45 is a sectional view of yet another vaporizer 60.

FIG. 46 is a sectional view of the vaporizer 60 of FIG. 45 taken in aplane shown by the arrows H—H in FIG. 45.

FIG. 47 is a figure showing still another vaporizer 70.

FIG. 48 is a figure showing a procedure for measuring in vaporizationperformance appraisal.

FIG. 49 is a figure showing the details of test materials which are usedas benchmarks.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, various embodiments of the present invention will bedescribed with reference to the appended drawings. Overall Structure ofthe Vaporizing system

FIG. 1 is a figure showing the general structure of the vaporizingsystem. This liquid substance vaporizing system is comprised of a liquidsubstance supply device 1 and a vaporizer 2 Liquid substance which hasbeen supplied from the liquid substance supply device 1 to the vaporizer2, after having been vaporized in said vaporizer 2, is supplied to a CVDreactor provided in a CVD device. Various liquid substances may be usedin such a MOCVD process, for example a liquid organometal such as Cu orTa, or an organometallic solution where an organometal such as Ba, Sr,Ti, Pb, or Zr is dissolved in an organic solvent. The liquid substancemay be referred to as the CVD source.

Substance containers 3A, 3B, and 3C which are provided in the liquidsubstance supply device 1 are charged with quantities 4A, 4B, and 4C ofliquid substances which are to be used for the MOCVD process. Forexample, if a BST (Ba—Sr—Ti oxide) film is to be formed, the liquidsubstances 4A, 4B, and 4C may respectively be the raw materials Ba, Sr,and Ti dissolved in an organic solvent such as THF (tetrahydrofuran).Furthermore, a quantity of the raw solvent THF is charged into a solventcontainer 3D. It should be noted that the number of the containers 3Athrough 3D is not limited to four; an appropriate number should beprovided for the number of types of raw material which are to beemployed.

A charge gas line 5 is connected to all the containers A through 3D, andtransfer lines 6A through 6D are connected to said containers 3A through3D respectively. When charge gas is supplied via the charge line to thecontainers 3A through 3D, the pressure of this charge gas is applied tothe surfaces of the masses of liquid substance 4A through 4C and themass of solvent 4D which are charged into the containers 3A through 3Drespectively. As a result, the liquid substances 4A through 4C and thesolvent 4D are expelled towards the respective transfer lines 6A through6D. These liquid substances 4A through 4C and the solvent 4D which areexpelled into the respective transfer lines 6A through 6D flow into atransfer line 6E due to the effects of the gas pressure, and are mixedtogether within this transfer line 6E.

Carrier gas from the carrier gas line 7 is also supplied into thetransfer line 6E. This carrier gas, the liquid substances 4A through 4C,and the solvent 4D within the transfer line 6E are supplied towards thevaporizer 2 in the state of a two-phase-flow of liquid phase and gasphase. Carrier gas is also supplied to the vaporizer 2 via a carrier gasline 7, and the substances which have been vaporized therein aretransported towards the CVD reactor (not shown) by the carrier gas.

An inert gas such as nitrogen gas or argon gas is used as the carriergas. It is desirable to reduce the amounts of the liquid substances 4Athrough 4C and of the solvent 4D which remain behind in the transferlines 6A through 6E to the minimum, and therefore, in this preferredembodiment of the present invention, ⅛ inch conduit is used for thetransfer lines 6A through 6E.

Mass flow meters 8A through 8D and flow rate control valves 9A through9D which can be cut off are provided within each of the transfer lines6A through 6D, respectively. While observing the flow rates of theliquid substances 4A through 4C and of the solvent 4D via the mass flowmeters 8A through 8D, the flow rate control valves 9A through 9D arecontrolled so that said flow rates of the liquid substances 4A through4C and of the solvent 4D may be set to their most suitable values. Itshould be noted that it would be acceptable also to provide a mixer inthe transfer line 6E directly before the vaporizer, so as to enhance thestate of mixing of the various liquid substances therein. Furthermore,instead of the flow rate control valves 9A through 9D which control theflow rates of the various liquid substances 4A through 4D and of thesolvent 4D, it would also be acceptable to perform this flow control byusing pumps such as plunger pumps or the like.

Explanation of the Liquid Substance Supply Device

FIG. 2 is a figure showing the details of the liquid substance supplydevice which is the preferred embodiment of the present invention. InFIG. 2, the structure of the transfer lines which are related to thesubstance containers 3B and 3C is omitted, since it is the same as thatof the transfer line for the substance container 3A. First, thepositions of arrangement of the mass flow meters 8A through 8D and theflow rate control valves 9A through 9D will be explained. Although inprior art devices, as described above, a type of mass flow controller isused in which a mass flow meter and a flow rate control valve arecombined, by contrast, with the liquid substance supply device accordingto this preferred embodiment of the present invention, independent massflow meters 8A through 8D and flow rate control valves 9A through 9D areprovided in each of the transfer lines 6A through 6D.

The mass flow meters 8A through 8D are thermal mass flow rate meters,and they take advantage of the fact that the energy which is required toraise the substance flow by a specified temperature is proportional tothe mass flow rate. Each of these mass flow meters 8A through 8Dcomprises a heater for warming up the mass flow and a pair oftemperature meters for measuring the temperature difference in thedirection of the mass flow. The flow meters 8A through 8D control theheat amount q of the heaters so as to make the temperature difference ΔTalong the direction of flow equal to a specified value. Since the massflow rate is proportional to the heat amount q which is being suppliedat this time, conversely, the mass flow rate can be obtained from theheat amount q.

With the liquid substance supply device shown in FIG. 2, the mass flowmeters 8A through 8D are disposed at positions in their transfer lines6A through 6D which are close to the containers 3A through 3D, and theflow rate control valves 9A through 9D are disposed at positions intheir transfer lines 6A through 6D which are close to the vaporizer 2.As a result, along with it becoming possible to prevent thermalinfluence of the vaporizer 2 from affecting the mass flow meters 8Athrough 8D, it is also possible to anticipate enhanced responsiveness.

FIG. 3 is a figure showing an external view of the flow rate controlvalves 9A through 9D. These flow rate control valves 9A through 9D areconnected to a block 90 by respective ports 91, 92, 93, and 94.Internally to the block 90 there are formed conduits 96A through 96Ewhich respectively correspond to the transfer lines 6A through 6E. Theabove described ports 91 through 94 are connected respectively to theconduits 96A through 96D, and the two opposite ends of the conduit 96Eare connected to ports 95 and 96. Open/close valves V9 and V6, shown inFIG. 2, are provided to the ports 95 and 96 connected to the conduit 96Erespectively.

The liquid substances 4A through 4C and the solvent 4 d are conducted tothe conduits 96A through 96D via the flow rate control valves 9A through9D respectively, and these flows then mix together in the conduit 96E.Carrier gas is supplied to the conduit 96E through the port 95. As aresult, a mixture of the liquid substances 4A through 4C and the carriergas in the two phase flow state of liquid phase and gas phase is presentin the conduit 96E. The liquid substance present in this two phase flowstate of liquid phase and gas phase is supplied into the vaporizer 2shown in FIG. 2 via the open/close valve V6.

Since only the flow rate control valves 9A through 9D, which areprovided in positions remote from the corresponding mass flow meters 8Athrough 8D, are connected to the block 90, thereby it is possible tomake the block 90 compact. Since not only is the block 90 provided inthe vicinity of the vaporizer 2, but also the flow rate control valves9A through 9D are employed which have the additional function of cutoffvalves, thereby it is possible to minimize the conduit volume betweenthe flow rate control valves 9A through 9D and the vaporizer 2. As aresult, it is possible to enhance the responsiveness of flow ratecontrol. Furthermore it is possible to minimize the volume of conduitthrough which the mixture flows, so that it i possible to reducedeterioration etc. of the liquid substance due to stop or stay.

Returning to FIG. 2, the substance container 3A and the solventcontainer 3D are connected to the charge gas line 5 and the transferlines 6A and 6D via connectors C which can be attached and removedindividually. Four port three valve directional control valve assemblies10A and 10D of unitary construction are provided between the connectorsC and the containers 3A and 3D respectively. Thanks to this structure,each of the containers 3A and 3D can be attached or removed as a unittogether with each of four port three valve directional control valveassemblies 10A and 10D.

This liquid substance supply device 1 is provided with auxiliary lines11 and 12 for performing evacuation, gas purging, solvent rinsing,liquid substitution, and so on of the transfer lines 6A and 6D. Theseauxiliary lines 11 and 12 are connected to a drain tank 13 whichreceives waste fluid during solvent rinsing or liquid substitution.Sensors LS1 and LS2 are provided to the drain tank 13 for detecting ahigh level of waste fluid within said tank. A vacuum evacuation line 14is connected to the drain tank 13 for bringing the interior of saiddrain tank 13 to a low pressure state. The auxiliary line 11 isconnected to the transfer lines 6A and 6D, respectively, via three porttwo valve directional control valve assemblies 15A and 15D which are ofunitary construction. Furthermore, an observation device 16 is providedin the auxiliary line 11, and, by looking through this observationdevice 16, it is possible to check the state of the substance which isflowing through said line 11, in other words whether said substance isliquid or gaseous. It should be noted that the details of the structuresof the four port three valve directional control valve assemblies 10Aand 10D, the three port two valve directional control valve assemblies15A and 15D, and the observation device 16 will be describedhereinafter.

Open/close valves V1 through V10 are provided in the charge gas lines 5,the transfer lines 6A, 6D, and 6E, the carrier gas line 7, the auxiliarylines 11 and 12, and the vacuum evacuation line 14 respectively. Vacuumevacuation, gas purging, and solvent rinsing are performed byappropriately changing over the open and closed states of the open/closevalves V1 through V10 and the switchover states of the three port twovalve directional control valve assemblies 15. Moreover, check valves17A and 17D are respectively provided in the charge gas lines 5, andfilters 18A and 18D are respectively provided in the transfer lines 6Aand 6D.

With the liquid substance supply device 1 shown in FIG. 2, in order toensure stability of fluid supply, along with providing in the transferlines 6A and 6D the filters 18A and 18D which hinder the generation ofbubbles, it is also arranged to reduce the dead volume in the conduitsto as low a value as possible in order to hinder the development ofprecipitates in the liquid substance. FIG. 4 is a sectional view of thefilter 18A. A sheet shaped filter element F21 is disposed within thebody F20 of the filter 18A provided in the transfer line 6A, orientedalmost perpendicularly to the direction of fluid flow. It should benoted that the filter 18D shown in FIG. 2 has exactly the same structureas the filter 18A.

A layered mesh with material such as stainless steel (SUS) wire may beused for the filter element F21. In this preferred embodiment, thefilter element F21 is made with layers of two types of mesh, oneconsisting of fine diameter mesh and the other consisting of coarsediameter mesh. Due to this, the filter 18A presents a low pressure lossas compared to prior art sintered type filters, and moreover has adesirable flow regulation action, and suppresses the occurrence ofbubbles, thus stabilizing the flow rate. Furthermore, the strength ofthe filter element F21 is enhanced by using not only the fine diametermesh but also the coarse diameter mesh. Yet further, it would also beacceptable to use a combination of layers of PTFE mesh for the filterelement F21, and in this case the resistance is enhanced, by comparisonwith stainless steel mesh.

FIG. 5 is a figure showing a comparison between the performance of theabove filter 18A which uses the filter element F21, and the performanceof a prior art filter which uses a sintered type filter element. In FIG.5, there is shown the output of a mass flow controller positioned at adistance of 2 m from the filter 18A in a conduit of φ 1.6×0.5 when theTHF solvent was flowing at a flow rate of 0.8 ml/min. In the upperportion of FIG. 5 there is shown the case of a prior art sintered typefilter, and it is seen that the output wobbles somewhat upwards anddownwards due to the generation of bubbles. On the other hand the caseof the filter 18A of this preferred embodiment is shown in the lowerportion of FIG. 5, and it will be clear that the wobbling which waspresent in the prior art does not now appear, so that the flow rate isstabilized.

When performing flow rate control using a mass flow controller, itbecomes necessary to keep the pressure differential presented by themass flow controller above a minimum of 0.5 kg/cm² and it is easy forbubbles to be generated in the filter portion. Due to this, the filter18A described above operates very effectively with regard to flow ratestabilization.

The opening and closing of the various valves is controlled as shown inFIG. 6 when supplying the liquid substances 4A through 4C to thevaporizer 2. For the convenience of explanation of the open and closedstates of the valves, in FIG. 6, the symbols for the valves which areclosed are colored black. The flows of charge gas are shown by thebroken line arrows, while the flows of the liquid substances 4A through4C and of the solvent 4D are shown by the solid arrows. During liquidsubstance supply, the open/close valves V1, V3, and V5 through V10, thevalve units V22 of the three port two valve directional control valveassemblies 15A and 15D, and the valve units V31 and V33 of the four portthree valve directional control valve assemblies 10A and 10D are putinto the open state. On the other hand, the open/close valves V2, V4,and V5, the valve units V21 of the three port two valve directionalcontrol valve assemblies 15A and 15D, and the valve units V32 of thefour port three valve directional control valve assemblies 10A and 10Dare put into the closed state. The details of the structure of the threeport two valve directional control valve assemblies 15A and 15D and ofthe four port three valve directional control valve assemblies 10A and10D will be explained hereinafter.

When controlling the opening and closing states of the various valves asshown in FIG. 6, the charge gas flows into the substance containers 3Athrough 3C and into the solvent container 3D, so that the liquidsubstances 4A through 4C and the solvent 4D are expelled from thecontainers 3A through 3D into the transfer lines 6A through 6Drespectively. The liquid substances 4A through 4C and the solvent 4Dexpelled into the transfer lines 6A through 6D are transferred into thetransfer line 6E, in which they mix. Furthermore, the carrier gas flowsinto this transfer line 6E, so that the liquid substances in the mixedstate and the carrier gas form a mass in the two phase flow state ofliquid phase and gas phase, which is then supplied to the vaporizer 2.

Concrete Structural Example of the Three Port Two Valve DirectionalControl Valve Assemblies

FIGS. 7 through 11 are figures showing an example for the structure ofthe three port two valve directional control valve assembly 15. FIG. 7is a front elevation view of the three port two valve directionalcontrol valve assembly 15; FIG. 8 is a view thereof as seen in thedirection shown by the arrow A in FIG. 7; FIG. 10 is a sectional view ofthis valve assembly 15 taken in a plane shown by the arrows B—B in FIG.8; and FIG. 11 is a sectional view of this valve assembly 15 taken in aplane shown by the arrows C—C in FIG. 10. Furthermore, FIG. 9 is a flowdiagram for this three port two valve directional control valve assembly15. As shown in this FIG. 9 flow diagram, this three port two valvedirectional control valve assembly 15 comprises two open/close valvesV21 and V22 in a unitary structure, and has three ports P1, P2, and P3.In this preferred embodiment, the open/close valves V21 and V22 will betermed the valve units V21 and V22.

The reference symbols 150A and 150B denote valve drive sections whichare driven by externally supplied compressed air. As shown in FIG. 10, apair of diaphragms 152A and 152B related to the valve units V22 and V21are provided in a body 151. Opening and closing operation of the valveunits V22 and V21 is respectively performed by pistons 153A and 153Bwhich are driven in the upwards and downwards directions in the figure.

In the open/closed state shown in FIG. 10, the piston 153A is driven bythe biasing force of a spring 155A in the upwards direction in thefigure, so that the diaphragm 152A is pressed against a valve seat 154A.On the other hand, the piston 153B is driven by the biasing force of aspring 155B in the downwards direction in the figure, so that thediaphragm 152B is pressed against a valve seat 154B. As a result theport P1 and the port P2 are cut off from one another, and the port P1and the port P3 are also cut off from one another.

When, in the state shown in FIG. 10, compressed air is supplied to theair inlet 156A, then the piston 153A is driven in the downwardsdirection in the figure by the pressure of this air. As a result, thediaphragm 152A is driven away from the valve seat 154A against which itwas previously pressed, and the port P1 and the port P2 are communicatedtogether. On the other hand, when compressed air is supplied to the airinlet 156B, then the piston 153B is driven in the upwards direction inthe figure by the pressure of this air. As a result, the diaphragm 152Bis driven away from the valve seat 154B against which it was previouslypressed, and the port P1 and the port P3 are communicated together.

With the three port two valve directional control valve assemblies 15Aand 15D shown in FIG. 2, the ports P1 and P2 are connected to thetransfer lines 6 (6A and 6D), and the port P3 is connected to theauxiliary line 11. For example, when the liquid substance 4A is expelledfrom the substance container 3A into the transfer line 6A, along withopening the valve unit V22 of the three port two valve directionalcontrol valve assembly 15A, the valve unit V21 is closed, and the liquidsubstance 4A is conducted from the port P1 to the port P2 as shown bythe flow R1 in FIG. 9. On the other hand, when as will be explainedhereinafter conduit rinsing is being performed in case that thesubstance container 3A is removed and attached, along with closing thevalve unit V22, the valve unit V21 is opened, and the waste rinsingfluid is conducted from the port P1 to the port P3 as shown by the flowR2 in FIG. 9.

When the liquid substance 4A is being expelled to the transfer line 6Aas shown by the flow R1 in FIG. 9, the conduit portion L21 constitutesdead volume. On the other hand, when the waste rinsing fluid is flowingas shown by the flow R2 is FIG. 9, the conduit portion L20 constitutesdead volume. As shown in FIG. 10, the port P1 is provided between thediaphragm 152A and the diaphragm 152B. Due to this, the conduit L20 isconstituted by the space between the port P1 and the diaphragm 152A,while the conduit L21 is constituted by the space between the port P1and the diaphragm 152B. Since in the prior art the portions whichcorresponded to the valve units V21 and V22 were constituted byindependent open/close valves, the portions which corresponded to theconduits L20 and L21 were constituted by conduits. By comparison withthe structure of this type of prior art, in this preferred embodiment,since the three port two valve directional control valve assembly 15 isused, it is possible to make the dead volumes of the branch portions ofthe three-way branched conduit system much smaller.

Concrete Structural Example of the Four Port Three Valve DirectionalControl Valve Assemblies

Next, the four port three valve directional control valve assemblies 10(10A and 10D) will be explained. FIGS. 12 and 13 are figures showing oneof these four port three valve directional control valve assemblies 10:FIG. 12 is a plan view thereof, while FIG. 13 is a view thereof as seenin the direction shown by the arrow D in FIG. 12. Four ports P11 throughP14 are provided in a body 101, and the reference numerals 100A through100C denote drive sections. FIG. 14 is a flow diagram for this four portthree valve directional control valve assembly 10. The four port threevalve directional control valve assembly 10 is of unitary structure, andcomprises three valve units V31, V32, and V33.

FIG. 15 is a sketch figure showing the structures within the body 101.Each of the valve units V31 through V33 has the same structure, and theycompose respective diaphragms 112A, 112B, and 112C, respective pistons113A, 113B, and 113C, and respective valve seats 114A, 114B, and 114Cwhich are all provided within the body 101. Since the drive mechanismsfor the pistons 113A through 113C in FIG. 15 are generally the same asthose shown in FIG. 10 for the three port two valve directional controlvalve assembly 15 and described above, explanation thereof will becurtailed. In the state shown in FIG. 15, each of the diaphragms 112Athrough 112C is pressed by its respective piston 113A through 113Cagainst its respective valve seat 114A through 114C. As a result, all ofthe valve units V31 through V33 are in their closed states.

When the piston 113A is driven in the leftwards direction as seen in thefigure from the state shown in FIG. 15, the corresponding diaphragm 112Ais removed away from its valve seat 114A, and the ports P11 and P12 arecommunicated with one another. Furthermore, when the piston 113C isdriven in the rightwards direction as seen in the figure from the stateshown in FIG. 15, the corresponding diaphragm 112C is removed away fromits valve seat 114C, and the ports P13 and P14 are communicated with oneanother. Within the body 101, a conduit 115 is formed which connects tothe port P11, and a conduit 116 is formed which connects to the portP13. When the piston 113B is driven in the upwards direction as seen inthe figure from the state shown in FIG. 15, the corresponding diaphragm112B is removed away from its valve seat 114B, and the conduit 115 andthe conduit 116 are connected to one another. As a result, the port P11and the port P13 are communicated with one another.

With the liquid substance supply device shown in FIG. 2, the ports P11are connected to connectors C on the charge gas line 5, while the portsP12 are connected to the substance container 3A and to the solventcontainer 3D. Furthermore, the ports P13 are connected to connectors onthe transfer lines 6 (6A and 6D), while the ports P14 are connected tothe substance container 3A and the solvent container 3D.

For example, when the liquid substance 4A is expelled from the substancecontainer 3A to the transfer line 6A, as shown in FIG. 6, the valve unitV32 is closed while the valve units V31 and V33 are opened. The chargegas flows from the port P11 to the port P12 along the path R3 shown inFIGS. 6 and 14 and is conducted into the substance container 3A. Theliquid substance 4A in the substance container 3A is conducted from theport P14 to the port P13, and is led into the transfer line 6A.Furthermore, during gas purging and conduit rinsing which will bedescribed hereinafter, the valve units V31 and V33 of FIG. 14 are closedwhile the valve unit V32 is opened, and the charge gas or the rinsingsolvent flows from the port P11 to the port P13 along the path RG.

With this four port three valve directional control valve assembly 10 aswell, just as with the three port two valve directional control valveassembly 15 described above, it is possible to reduce the dead volume toa minimum. In other words, in the case of a building a circuit like thatof FIG. 14 using independent open/close valves such as in the prior art,the valve units V31 through V33 are constituted by various open/closevalves. In this case, since the portions shown by the reference numerals120 and 121 in FIG. 14 are constituted as conduits, it is inevitablethat the dead volume is comparatively great. On the other hand, with thepreferred embodiment described above, since it is possible to minimizethe volume of the conduits 115 and 116 by using the four port threevalve directional control valve assemblies 10 which are of unitarystructure, accordingly it becomes possible to reduce the dead volume toa minimum.

As described above, the four port three valve directional control valveassemblies 10A and 10D are provided on the sides of the substancecontainer 3A and the solvent container 3D respectively at the respectiveconnectors C. When supplementing further quantities of the relevantsubstances, each of the four port three valve directional control valveassemblies 10A and 10D and each of the containers 3A and 3D are detachedas a combined unit at the connectors C. For example, in the case thatthe substance container 3A is to be detached at the connectors C fromthe charge gas line 5 and the transfer line 6A, as shown in FIG. 16,from the state shown in FIG. 6, the open/close valves V3 and V6 and thevalve units V22, V31, and V33 are closed, while the open/close valves V2and V4 and the valve units V21 and V32 are opened.

When the opened and closed states of the valves are controlled in thismanner, the solvent 4D which has been expelled from the solventcontainer 3D into the transfer line 6D flows in order from theopen/close valve V2 to the auxiliary line 12, thence to the open/closevalve V4, thence to the valve unit V32, thence to the valve unit V21,and thence to the auxiliary line 11, thence to be exhausted into thedrain tank 13. Due to the solvent 4D flowing along this path, the liquidsubstance 4A remaining within the conduit portion F1 shown in FIG. 16 bythick lines is rinsed away by the flow of this solvent 4D. The wastefluid after rinsing is exhausted via the auxiliary line 11 to the draintank 13. It should be understood that the conduit portion F1 correspondsto the ports P11 and P13 and the conduits 115 and 116 of FIG. 15.

When the rinsing of the conduit portion F1 has been completed, thesubstance container 3A and the four port three valve directional controlvalve assembly 10A are removed from the connectors C as a unit. And,after supplementing a further quantity of the liquid substance 4A intothe substance container 3A, the substance container 3A is againconnected to the connectors C. It should be noted that, after therinsing of the conduit portion F1 has been completed, furthermore, itwould also be acceptable to change over the opened and closed states ofthe valves as shown in FIG. 17, and to purge the interior of the conduitportion F1 with charge gas, so as to eliminate the remaining solventwithin the conduit F1.

By making the substance container 3A and the four port three valvedirectional control valve assembly 10A as a unit which can be removedfrom the lines 5 and 6A as described above, and moreover by making thesubstance container 3A so that it can be removed after the conduitportion F1 has been rinsed as shown in FIG. 16, it is ensured that noliquid substance remains within the conduit portion F1, which is theportion which is in contact with the atmosphere. As a result, even whenperforming the operations of attachment and detachment of the substancecontainer 3A, it is ensured that reaction products between the liquidsubstance 4A and atmospheric gases do not occur in the interior of theconduit portion F1.

If a resin material is to be used for the diaphragms 152A, 152B and 112Athrough 112C and for the valve seats 154A, 154B and 114A through 114C ofthe three port two valve directional control valve assemblies 15Athrough 15D and the four port three valve directional control valveassemblies 10A through 10D, it is desirable to use PEEK (polyether etherketone), PTFE (polytetrafluoroethylene), PI (polyimide), PBI(polybenzimidazole) or the like, which have superior heat resistance andchemical resistance. It is possible to anticipate enhanced durability byusing this type of substance.

Explanation of the Rinsing Operation

Next the operation of rinsing, which is performed before starting thevaporization operation, will be explained. Herein, the operations ofvacuum evacuation, gas purging, and solvent rinsing which are performedduring the rinsing operation will be explained. In an actual rinsingoperation, these processes are employed in various orders andcombinations in order to perform rinsing of the interiors of the linesefficiently. For example, vacuum evacuation (or gas purging) and thensolvent rinsing may be performed in order, or vacuum evacuation and gaspurging may be performed several times in succession, and then solventrinsing may be performed. Furthermore, after the solvent rinsingoperation, it may be desirable to perform gas purging in order toeliminate remaining rinsing liquid left over from the rinsing operation.

(1) Vacuum Evacuation

First, the operation of vacuum evacuation of the transfer lines 6Athrough 6D and of the auxiliary lines 11 and 12 using the evacuationline 14 will be explained. FIG. 18 is a figure showing the open andclosed states of the valves during vacuum evacuation. The open/closevalves V6, V9, and V10 and the valve units V31 and V33 of the four portthree valve directional control valve assemblies 10A and 10D are putinto the closed state, while the other valves are put into the openstate. When the opening and closing of the various valves is controlledin this manner, the charge gas line 5, the transfer lines 6A through 6D,and the auxiliary lines 11 and 12 are evacuated to vacuum via the vacuumevacuation line 14 by a vacuum evacuation device not shown in thefigures.

(2) Gas Purging

FIG. 19 is a figure showing the open and closed states of the valvesduring gas purging. In FIG. 19, the open/close valve V10 of FIG. 18 ischanged over from the closed state to the opened state. As shown by thebroken line in the figure, the charge gas flows into the charge gas line5, the transfer lines 6A through 6D, and the auxiliary lines 11 and 12,and is exhausted to the drain tank 13 which is connected to the vacuumevacuation line 14.

(3) Solvent Rinsing

FIG. 20 is a figure showing the open and closed states of the valvesduring solvent cleansing. In this process, rinsing of the conduits isperformed using the solvent 4D in the solvent container 3D. Theopen/close valve V3, the valve units V21 of the three port two valvedirectional control valve assemblies 15A and 15D, and the valve unitsV32 of the four port three valve directional control valve assembly 10Dare changed over from the open state to the closed state. And the valveunits V31 and V33 of the four port three valve directional control valveassembly 10D are changed over from the closed state to the opened state.

Pressurized charge gas from the charge gas line 5 is supplied into thesolvent container 3D, and the solvent 4D in this solvent container 3D isexpelled towards the transfer line 6D. The solvent 4D which is expelledinto the transfer line 6D is divided, at the branch point P40, so as toflow through said transfer line 6D in the direction to the flow ratecontrol valve 9D at the upper portion of the figure, and also so as toflow via the open/close valve V2 into the auxiliary line 12.

The solvent 4D which has flowed into the auxiliary line 12 from thebranch point P40 is again divided into two portions at the branch pointP41. The portion of the flow which is branched at the branch point P41in the downward direction as seen in the figure flows in order to theopen/close valve V4, thence to the valve unit V32 of the four port threevalve directional control valve assembly 10A, thence to the valve unitV22 of the three port two valve directional control valve assembly 15A,and thence into the transfer line 6A, and is conducted in the transferline 6A in the direction of the flow rate control valve 9A.

On the other hand, the portion of the flow of the solvent 4D which isbranched at the branch point P41 in the upward direction as seen in thefigure is conducted towards the substance container 3B via the auxiliaryline 12. For the substance containers 3B and 3C as well, there areprovided conduit systems which are the same as the conduit system forthe substance container 3A—in detail, there are provided in thesesystems elements which are analogous to the auxiliary line 12 shown onthe right side of the open/close valve V2 in the figure, the charge gasline 5, the transfer line 6A, the auxiliary line 11, the valves whichare disposed in these lines, and the like. However, in FIGS. 2 and 18,the conduit systems for the substance containers 3B and 3C are omitted.In the case of the substance containers 3B and 3C as well, just as inthe case of the substance container 3A, the solvent 4D is flowed in, andis conducted within the transfer lines 6B and 6C in the directions ofthe flow rate control valves 9B and 9C. The flows of solvent 4D in thetransfer lines 6A through 6D mix together in the transfer line 6E, andthe resulting flow of solvent is stored into the drain tank 13 via theopen/close valve V5 and the auxiliary line 11.

Explanation of the Fluid Substitution Operation

After the operations of vacuum evacuation, gas purging, and rinsing ofthe transfer lines 6A through 6D by solvent rinsing have been completed,the operation of fluid substitution is performed. By this operation offluid substitution, the transfer lines 6A through 6C are filled up withthe respective liquid substances 4A through 4C, and the transfer line 6Dis filled up with the solvent 4D. It should be noted that if, after therinsing operation has been completed, the interiors of the conduits arefilled up with charge gas, an operation of “gas to liquid” substitutionis performed, while, if the interiors of the conduits are filled up withthe solvent 4D, an operation of “liquid to liquid” substitution isperformed.

FIG. 21 is a figure showing the open and closed states of the valvesduring fluid substitution. The open/close valves V1, V3, V5, V7, V8, andV10, the valve units V22 of the three port two valve directional controlvalve assemblies 15A and 15D, and the valve units V31 and V33 of thefour port three valve directional control valve assemblies 10A and 10Dare put into their open states. On the other hand, the open/close valvesV2, V4, V6, and V9, the valve units V21 of the three port two valvedirectional control valve assemblies 15A and 15D, and the valve unitsV32 of the four port three valve directional control valve assemblies10A and 10D are put into their closed states.

The substance in the interiors of the transfer lines 6A through 6C, i.e.charge gas or rinse liquid (the solvent 4D), is replaced by therespective liquid substances 4A through 4C. Within the transfer line 6D,the charge gas or the rinse liquid is replaced by the solvent 4D. Theliquid substances 4A through 4C and the solvent 4D which are suppliedinto the transfer line 6E from the transfer lines 6A through 6D aremixed together in the transfer line 6E. These liquid substances areexhausted in this mixed state via the open/close valve V5 and theauxiliary line 11 into the drain tank 13.

During this substitution operation, by using an observation device 16,it is possible to observe whether or not all of the charge gas orrinsing liquid in the conduits has been replaced by the liquidsubstances 4A through 4C and the solvent 4D. FIG. 22 is a general figureshowing this observation device 16. A conduit 160 which is formed withinthe observation device 16 is connected midway in the auxiliary line 11.The liquid (charge gas or a liquid substance 4A through 4C) which hasflowed into the observation device 16 from the auxiliary line portion 11connected to the upper side thereof in the figure is conducted throughthe conduit 160 and then flows into the auxiliary line portion 11 whichis connected to the lower side of the observation device 16 in thefigure.

The light-transparent windows 161, which are made from a substance whichis transparent to light such as glass, are provided midway along theconduit 160. A light emitting element 162 and a light receiving element163 are provided within the observation device 16, confronting oneanother on opposite sides of the portion of the conduit 160 in which thewindows 161 are provided, and these elements are controlled by a controlsection 164. For example, a LED may be used for the light emittingelement 162, while a photodiode or a phototransistor or the like may beused for the light receiving element 163.

Since the proportion of light which gets through a mixture of the liquidsubstances 4A through 4C and the solvent 4D flowing in the conduit 160is lower, by comparison to the case in which charge gas or the solvent4D is flowing therein, therefore the amount of light received in theformer case by the light receiving element 163 is also lower. A suitablestandard amount W3 of received light is set which satisfies the relationW1>W3>W2, where W1 is the amount of light which is received when solvent4D or charge gas is flowing in the conduit 160, and W2 is the amount oflight which is received when a mixture of the liquid substances 4Athrough 4C and the solvent 4D is flowing in the conduit 160. If theamount W of received light changes from being greater than or equal toW3 to being less than W3, then the control section 164 determines thatthe “gas to liquid” or “liquid to liquid” substitution in the transferlines 6A through 6D has been completely finished, and accordingly thesubstitution operation is terminated. When the substitution operation isterminated, the open and closed states of the various valves are changedover to those shown in FIG. 6, and the vaporization process iscommenced.

It should be noted that, although in the above example the observationdevice 16 which was employed during liquid substitution for checking theprogress of the substitution operation was provided in the auxiliaryline 11, it would also be possible, for example, to determine upon thegeneration of bubbles or the presence or absence of liquid by providingobservation devices 16 in the transfer lines 6A through 6D. Furthermore,it would also be acceptable to provide an absorptiometric analysisdevice 110 such as the one disclosed in Japanese Patent Laid-OpenPublication Heisei 11-345774 in the auxiliary line 11 of FIG. 21, inorder thereby to evaluate deterioration of the liquid or the state ofmixing.

When measuring the remaining amounts of the liquid substances 4A through4C and of the solvent 4D in the substance containers 3A through 3C andin the solvent container 4D, normal fluid surface sensors cannot beemployed, from the point of view of chemical resistance. In thisconnection, in the preferred embodiment described above, it is arrangedto determine these remaining amounts by calculating the product of timeand the flow rates measured by the mass flow meters 9A through 9D.Furthermore, it would also be possible to determine the amounts ofremaining liquid in the containers 3A through 3D from the change ofpressure of the pressurization gas (the charge gas) in said containers.

FIG. 23 is a sectional view showing the detailed structure of thesubstance container 3A of FIG. 2. A gas pressure gauge 301 is connectedto a conduit 300 on the charge gas line side of this substance container3A. A remaining quantity measurement device 302 calculates the quantityof liquid which remains in the substance container 3A, based upon thechange of pressure detected by the pressure gauge 301. When measuringthis remaining quantity, the open/close valve V1 is closed after thepressurized charge gas has been supplied into the substance container3A, and the change of pressure while a predetermined amount of theliquid substance 4A is outputted or while a predetermined time elapsesis measured by the pressure gauge 301. The amount which is outputtedfrom the substance container 3A at this time is measured by the massflow meter 8A shown in FIG. 21.

In this connection, if the case when the level of the surface of theliquid changes from L1 to L2 and the case when the level of the surfaceof the liquid changes from L3 to L4 are compared, the amount by whichthe pressure in the container 3A changes is different, even though thesame amount of the liquid substance 4A is outputted. For example, thepressure change in the case when the level of the surface of the liquidchanges from L1 to L2 is greater than the pressure change when the levelof the surface of the liquid changes from L3 to L4. The relationshipbetween the amount of remaining liquid and the change of pressure isstored in advance in the remaining quantity measurement device 302, andit calculates the quantity of remaining liquid based upon thisrelationship and the change of pressure detected by the pressure gauge301. The relationship may be stored as expressions.

In the exemplary construction for the substance container 3A shown inFIG. 23, the pressurized charge gas is conducted into the substancecontainer 3A to pressurize the liquid substance 4A which is chargedtherein, and the liquid substance 4A is expelled into the transfer line6A by the pressure of this charge gas. Since the pressurized charge gascomes into direct contact with the surface of the liquid, it is easy forthe charge gas to become dissolved in the liquid substance 4A. As aresult, it is easy for the charge gas to come out again in the transferline 6A to generate bubbles. FIGS. 24 and 25 show variant possibilitiesfor the substance container 3A which can reduce the quantity of gasdissolved in this manner.

FIG. 24 is a sectional view showing a first variant embodiment of thesubstance container, while FIG. 25 is a sectional view showing a secondvariant embodiment thereof. The container 30 according to the firstvariant embodiment shown in FIG. 24 is of double structure, andcomprises an outer casing 303 and an inner bag 304. The inner bag 304,which is housed in the interior of the outer casing 303 and isgas-tight, may be made from a chemical resistant substance such as PTFEor the like. The bottom portion of the inner bag 304 is fixed to theouter casing 303. The liquid substance 4A is charged into the inner bag304, and the space S between the inner bag 304 and the outer casing 303receives the pressurized charge gas via the charge gas line 5. When theinner bag 304 is thus squeezed in the horizontal direction as seen inthe figure by the pressure of the charge gas, the liquid substance 4A insaid inner bag 304 is expelled towards the transfer line 6A via theconduit 305 and the four port three valve directional control valveassembly 10A.

The container 31 according to the second variant embodiment shown inFIG. 25 comprises an outer casing 303 and, housed therein, instead ofthe inner bag 304 of the FIG. 24 variant container 30, a bellows 311which is made of metal such as stainless steel (SUS) or PTFE. The chargegas is fed into the space S between the bellows 311 and the casing 303,and the bellows 311 is squeezed in the upwards direction in the figureby the pressure of this charge gas. As a result, the liquid liquidsubstance 4A charged into said bellows 311 is expelled towards thetransfer line 6A via the conduit 312 and the four port three valvedirectional control valve assembly 10A. In this manner, with these twovariant embodiments of the container 30 and 31, the liquid substance 4Ais charged into the inner bag 304 or into the bellows 311, andaccordingly it does not come into contact with the charge gas in thecontainer. As a result, it is possible to prevent any moisture componentwhich the charge gas may contain from being absorbed by the liquidsubstance 4A.

FIG. 26 is a sectional view showing a third variant embodiment of thesubstance container. This substance container comprises two bellows 321and 322. The upper and lower ends of the upper bellows 321 arerespectively fixed to an upper side plate 323A and a movable plate 323B.Moreover, the upper and lower ends of the lower bellows 322 arerespectively fixed to the movable plate 323B and a lower side plate323C. The upper side plate 323A and the lower side plate 323C areconnected together by rods 324 and nuts 325, and thereby a certainpredetermined gap is maintained between said upper side place 323A andsaid lower side plate 323C.

A conduit 326 is provided so as to pierce through the upper side plate323A. The liquid substance 4A is charged into the interior of the upperbellows 321, and is exhausted therefrom, via this conduit 326. On theother hand, the charge gas is supplied to the interior of the lowerbellows 322 via a conduit 327 and a conduit 328 which is formed in thelower side plate 323C. The conduit 327 passes through the upper plate323A and the movable plate 323B, while it is fixed to the lower sideplate 323C. It should be understood that the conduits 326 and 327 areconnected to the four port three valve directional control valveassembly 10A, described above.

When in the state shown in FIG. 26 charge gas is again supplied to theinterior of the lower bellows 322, the bellows 322 is distended in thevertical direction and pushes the movable plate 323B in the upwardsdirection in the figure. As a result, the upper bellows 321 is squeezedin the vertical direction, and the liquid substance 4A charged into itis expelled via the conduit 326 towards the transfer line. It ispossible to determine the amount of the liquid substance 4A in the upperbellows 321 from the position in the vertical direction of the movableplate 323B.

For the material from which the bellows 321 is manufactured, a metalwhich has excellent resistance such as stainless steel (SUS), or acomposite resin material such as PTFE or the like, may be used.Furthermore although, in the example shown in FIG. 26, the bellows 321for the liquid substance was squeezed by the supply of charge gas to theinterior of the lower bellows 322, it would also be acceptable tosqueeze the upper bellows 321 in the vertical direction by using an aircylinder or a pantograph mechanism.

Explanation of the Vaporizer 2

FIG. 27 is a sectional view of the vaporizer 2. This vaporizer 2comprises a nozzle section 20 and a vaporization chamber 21. The liquidsubstances 4A through 4C are sprayed in from the nozzle section 20 inthe form of a fine mist. These liquid substances which have been sprayedinto the vaporization chamber 21 from the nozzle section 20 are thenvaporized therein. The liquid mixture of the liquid substances 4Athrough 4C which has flowed in from the transfer line 6E and the carriergas which has flowed in from the carrier gas line 7 is supplied into adouble conduit 200 which is provided in the nozzle section 20. Sincethis carrier gas is used for atomizing the liquid substances 4A through4C, it will hereinafter be termed the atomization gas.

Heaters h1 through h6 for heating are provided in the vaporizationchamber 21, and the vaporization chamber 21 is maintained at atemperature which is higher than the vaporization temperature of theliquid substances 4A through 4C by these heaters. The liquid substances4A through 4C which have been sprayed into the interior of thevaporization chamber 21 from the nozzle section 20 in the verticallydownward direction in the figure, as shown by the double dotted lines,are vaporized therein. The vaporized liquid substances are supplied viaan exhaust aperture 24 to a CVD reactor not shown in the figures.

The transfer line 6E is connected to the nozzle section 20 of thevaporizer 2 by a coupling 22. FIG. 28 is an enlarged view of a portionof this coupling 22. This coupling 22 comprises a pair of sleeves 220 aand 220 b, a nut 221, a plug 222, and a metal gasket 223. A conduit 224from the transfer line 6E is arranged so as to pierce through the sleeve220 a in its axial direction, and is fixed to the sleeve 220 a bywelding or the like. The mutually opposing faces of the two sleeves 220a and 220 b are respectively formed with seal faces S1 and S2 each ofwhich projects axially as a ring shape. The metal gasket 223 is providedbetween these seal faces S1 and S2, and, when the plug 222 is screwedinto the nut 221, the conduit 224 is fixed to the nozzle section 20.1/16 inch stainless steel (SUS) pipe is used for the conduit 224, and atits portion denoted by C in the figure it is formed by swaging into athin tube of less than or equal to 1 mm in outer diameter. As a result,the mixed gas and liquid flow of liquid metal substances and carrier gasis smoothed, and it is possible very greatly to reduce the dead volume,which could otherwise be the cause of blockages of the liquid metalsubstance flow or of substance degeneration. With regard to thediametrical dimension of this thin tube portion, it should be set to themost suitable value in consideration of the flow rate and so on. In thefollowing discussion, the thin tube portion which extends below thesymbol C in the figure will be termed the internal conduit 200 a.

In the examples shown in FIGS. 27 and 28 the internal conduit 200 a wasmade by squeezing down the conduit 224 from the transfer line 6E byswaging and by processing it into a thin tube whose outer diameter isless than or equal to 1 mm, but in the variant examples shown in FIGS.29 and 30 the conduit 224 and the internal conduit 200 a are made asseparate conduit members, and they are joined together. In the caseshown in FIG. 29, the construction is implemented by inserting the uppertip portion of the internal conduit 200 a into the conduit 224 andwelding it therein. In the case shown in FIG. 30, the construction isimplemented by inserting the upper tip portion of the internal conduit200 a into the conduit 224 and crimping the outer surface of saidconduit 224. Both of these manufacturing methods are characterized bylow cost.

In the further variant shown in FIG. 31, the conduit 224 and theinternal conduit 200 a are connected together by taking advantage of thecoupling 22. The conduit 224 is fixed to the upper end portion of thesleeve 220 a by welding or the like. A tubular hole 232 which has athreaded portion 231 is formed in the sleeve 220 a. A ring shaped sealmember 233 which is made of PTFE is fitted around the outer periphery ofthe tip portion of the internal conduit 200 a, and this internal conduit200 a is inserted into the tubular hole 232 of the sleeve 220 a. A setscrew 234 which is fitted over the internal conduit 200 a is screwedinto the threaded portion 231 of the tubular hole 232, and the sealmember 233 provides a seal between the outer peripheral surface of theinternal conduit 200 a and the inner peripheral surface of the tubularhole 232. In this case, along with the cost being comparatively low,there is also the advantage that it is possible easily to change justthe internal conduit 200 a by itself which is particularly liable toblockage.

FIG. 32 is an enlarged view showing the portion E of FIG. 27. The doubleconduit 200 is made up of the internal conduit 200 a and an externalconduit 200 b. A gas-liquid mass made up from the liquid substances 4Athrough 4C and the carrier gas flows through the internal conduit 200 a,while the atomization gas flows through the annular space between theinternal conduit 200 a and the external conduit 200 b. The externalconduit 200 b is fixed to a water cooling block 201 by welding or thelike. The internal conduit 200 a is fixed to the sleeve 220 a describedabove. A cooling rod 202 is provided around the double conduit 200 incontact with its external conduit 200 b. As shown in FIG. 27, the endportion of the cooling rod 202 extends downwards as far as the lower endportion of the double conduit 200.

A male threaded portion 203 is formed at the upper end of the outerperipheral surface of the cooling rod 202. When this male threadedportion 203 of the cooling rod 202 is connected to a female threadedportion 205 which is formed in a concave portion 204 of the watercooling block 201, the cooling rod 202 is fixed to the water coolingblock 201. As shown in FIG. 27, a cooling water conduit 206 is formed inthe water cooling block 201, and cooling water which is supplied fromexternally via a cooling water pipe 207 circulates through this coolingwater conduit 206 and cools the water cooling block 201. The cooling rod202 is cooled by the water cooling block 201, and furthermore thecooling rod 202 cools the double conduit 200.

A casing 208 which surrounds the outer peripheral surface of the coolingrod 202 is provided at the lower portion of the water cooling block 201as seen in FIG. 27. A fixing flange 208 a is formed upon the lowerportion of the casing 208. The nozzle section 20 is attached to thevaporization chamber 21 by this flange 208 a being fixed to thevaporization chamber 21. It should be understood that, although in thispreferred embodiment of the present invention the water cooling block201 and the cooling rod 202 are formed as separate parts and are screwedtogether, it would also be acceptable, as an alternative, to form themas one unit. Furthermore, a substance whose heat transmission is good,such as copper, may be used as the material for the cooling rod 202.

FIG. 33 is an enlarged view showing the portion F of FIG. 27. An endportion 208 b of the casing 208 is made to be thin, and is connected tothe end portion of the external conduit 200 b by welding or the like. Asa result, a heat insulating space 209 in the interior of the casing 208and a vaporization chamber space 210 are separated from one another,which prevents the cooling rod 202 from being corroded by thevaporization gas. As shown in FIG. 27, it is arranged for the insulatingspace 209 to be evacuated via a pipe 208P. By evacuating the insulatingspace 209, transfer of heat from the casing 208 to the cooling rod 202due to convection is prevented.

The internal conduit 200 a projects more in the downward direction inthe figure than does the external conduit 200 b, and furthermore passesthrough a hole which is formed in the central portion of an orificemember 212 and projects therefrom. The atomization gas which has flowedin the downwards direction in the figure between the internal conduit200 a and the external conduit 200 b passes through a minute gap whichis defined between the orifice member 212 and the internal conduit 200 aand is spouted into the vaporization chamber space 210. This gap may,for example, be set to a very small dimension of 1 mm or less. When theliquid substances 4A through 4C are injected from the internal conduit200 a, they are atomized by this atomization gas, and the liquidsubstance in the form of mist is sprayed in the vaporization chamberspace 210.

With the vaporizer of this preferred embodiment, it is desirable to setthe end of the internal conduit 200 a to a state as somewhat projectingin the downwards direction from the orifice member 212. Adjustment ofthis amount of projection h is performed by varying the tightening forceof the coupling 22 shown in FIG. 28. In concrete terms, the dimensionsin the axial direction of the internal conduit 200 a are set so that theend of said internal conduit 200 a is at almost the same position in thedownwards direction as the lower surface of the orifice member whenattaching the coupling 22 with the screwing force which is required forsealing against the metal seal, and the minute adjustment of theprojection amount h is performed by re-screwing of the coupling 22.

The orifice member 212 is fixed to the casing end portion 208 b by anozzle ring 211. A seal member 213 is provided between the orificemember 212 and the casing end portion 208 b. A vaporization surface 211a of conical form is defined upon the nozzle ring 211, which is fittedto the end of the casing 208 like a box nut. This nozzle ring 211 is forpreventing the liquid substances 4A through 4C which have been sprayedfrom the nozzle section 20 from re-condensing upon the end portion ofsaid nozzle section 20, and it is kept at a high temperature by heatwhich is conducted to it via the flange 208 a (refer to FIG. 27) whichis fixed to the vaporization chamber 21. As a result, no non-vaporizedresidue are generated, even if the atomized liquid substances 4A through4C adhere to the vaporization surface 211 a.

The above described casing 208, nozzle ring 211, conduits 200 a and 200b etc. are made from stainless steel (SUS) or the like, in view ofcorrosion resistance and so on. On the other hand, the orifice member212 and the seal member 213 may be made from resin or a similar materialwhose heat insulating qualities are good, so as to diminish heattransfer from the nozzle ring 211 to the cooling rod 202. In particular,since the orifice member 212 and the seal member 213 are required tohave good chemical resistance with respect to the liquid substances 4Athrough 4C, it is desirable for them to be formed from PTFE(polytetrafluoroethylene) whose heat insulating properties, thermalresistance, and chemical resistance are excellent. Furthermore, it wouldalso be acceptable to form the orifice member 212 from PEEK (polyetherether ketone) whose hardness is greater, in order to prevent deformationdue to the high temperature environment or due to screwing the nozzlering 211.

In this manner, rise of temperature of the cooling rod 202 is preventedby forming the orifice member 212 or the seal member 213 from aninsulating material, so as to reduce transfer of heat from the nozzlering 212 to the cooling rod 202.

Explanation of the Cooling Benefit Obtained from the Cooling Rod 202

When vaporizing the liquid substances 4A through 4C with the vaporizer,it is necessary to prevent the generation of non-vaporized residue anddegradation of the liquid substances 4A through 4C due to heat history.To this end, it is necessary to subject the liquid substances 4A through4C to low pressure and increased temperature substantiallysimultaneously and moreover instantaneously. In this preferredembodiment, the cooling rod 202 is arranged to enclose the outerperiphery of the double conduit 200, and moreover the cooling rod 202 isprovided as extending to the vicinity of the spout portion of the doubleconduit 200. Due to this, the liquid substances 4A through 4C which areflowing through the internal conduit 200 a are sufficiently cooled untilimmediately before being spouted into the vaporization chamber space210.

The cooling rod 202 only comes into contact with the very thin endportion 208 b of the casing 208, and the insulating space 209 is formedbetween the cooling rod 202 and the casing 208. Since the orifice member212 and the seal member 213 which have excellent insulating performanceare interposed between the casing 208 and the nozzle ring 211 which isat high temperature, it is possible to reduce the transfer of heat tothe cooling rod 202 from the vaporization chamber 21 or the nozzle ring211 which are at high temperature.

FIG. 34 is a figure showing the temperature distribution in the axialdirection within the internal conduit 200 a when the vaporizationchamber 21 was heated up to 250 degrees C. The temperature of thecooling water was 8 degrees C., and the pressure within the insulatingspace 209 was 1333 Pa (=10 Torr). In FIG. 34, the temperature of theinternal conduit 200 a is shown along the vertical axis, while thedistance from the end of the cooling rod 202 measured in the upwarddirection in the figure is shown along the horizontal axis. The portionof this figure in which the distance along the horizontal axis isnegative is a portion relating to the case when the internal conduit 200a is projecting downwards from the end of the cooling rod 202. As shownin FIG. 34, even in an environment at a high temperature such as 250degrees C., the internal conduit 200 a is maintained at a sufficientlylow temperature, due to the effect of cooling by the cooling rod 202.For example, the portion of the rod about 10 mm from its tip is at about50 degrees C.

FIG. 35 is a figure qualitatively showing the changes in the temperatureand the pressure of one of the liquid substances before and aftervaporization. Graph No. 1 at the top of this figure relates to thevaporizer of this preferred embodiment, while Graphs Nos. 2 and 3 relateto prior art type vaporizers. In the FIG. 35 graphs, temperature andpressure are shown along the vertical axes, while time is shown alongthe horizontal axes. Furthermore, in each graph, the temperature and thepressure in the liquid state are shown in the left side region, whilethe temperature and the pressure after vaporization are shown in theright side region.

The graph No. 2 of FIG. 35 shows the changes of temperature and pressurewhen the device described in Japanese Laid-open Patent Publication No.Heisei 5-253402 is employed. With this device, the liquid substancewhich is supplied by the pump to the vaporizer is subjected to a lowpressure vaporization process, after having been heated up by contactwith a high temperature disk provided in the vaporizer. Furthermore, thegraph No. 3 of FIG. 35 shows the changes of temperature and pressurewhen the device described in Japanese Laid-open Patent Publication No.Heisei 8-508315 is employed. With this device, after the liquidsubstance has been heated up under pressure, it is soaked into a meshwhich is then subjected to low pressure, whereby said liquid substanceis vaporized.

Both in the case of graph No. 2 of FIG. 35 and also in the case of graphNo. 3, the intermediate state D, when the state of the liquid substancechanges from the room temperature high pressure state to the hightemperature low pressure state, is continued for a comparatively longtime period. In this intermediate state D, the liquid substance caneasily be degraded due to heat history, and the generation ofnon-vaporized residues and of blockages in the vaporizer and so on caneasily occur. On the other hand, in the case of the embodiment accordingto this preferred embodiment of the present invention, the intermediatestate D lasts for only a short time period, as shown in graph No. 1 ofFIG. 35, because the liquid substances 4A through 4C are cooled by thecooling rod 202 until directly before being spouted from the internalconduit 200 a. As a result, it is possible to reduce degradation of theliquid substances 4A through 4C, nonvaporized residues , and blockagesin the vaporizer and the like.

Explanation of Spray—Atomization Performance

The internal conduit 200 a is made as a thin tube of outer diameter lessthan or equal to 1 mm, and the flow rate of the liquid substances 4Athrough 4C and the carrier gas in this internal conduit 200 a isadjusted so that the two phase gas/liquid flow in the conduit becomes aring shaped (annular) spray flow. By a ring shaped spray flow is meant,that the flow rate of the gas phase in this two phase gas/liquid flow isgreat as compared to the flow rate of the liquid phase therein, and thata liquid film is present upon the conduit wall, with a large number ofaccompanying liquid droplets in the gas phase flow in the centralportion of the conduit as seen in its transverse cross section. Itshould be noted that the flow rate conditions for performing stableatomization will be described hereinafter.

Furthermore, the atomization performance does not only depend upon theflow rate of the liquid substances 4A through 4C and the carrier gas,and upon the dimensions of the conduit, as described above, but alsoupon the flow rate of the atomization gas which flows through theexternal conduit 200 b. FIG. 36 is a figure for explanation of therelationship between the liquid flow rate and the gas flow rate in theinternal conduit 200 a, the gas flow rate in the external conduit 200 b,and the stability of atomization. It should be understood that, whenperforming these measurements, THF was used as the liquid flowing in theinternal conduit 200 a, while nitrogen gas was used as the carrier gasand the atomization gas.

In FIG. 36, the flow rate of the carrier gas (in SCCM) is shown alongthe vertical axis, while the flow rate of the THF (in cc/min) is shownalong the horizontal axis. In these measurements, experiments wereperformed to distinguish between “stable atomization” which means thatcontinuous atomization was observed, and “unstable atomization” whichmeans that liquid droplets suddenly and discontinuously boil and thepressure in the vaporization chamber varied greatly. The “O” points inFIG. 36 denote data points at which stable atomization was observed,while the “X” points denote data points at which unstable atomizationwas observed. With regard to the atomization gas, the flow rate was 50SCCM at pressures from 1333 Pa (=10 Torr) to 6666 Pa (=50 Torr), whilethe primary pressure of the THF was 1.7 Mpa. Furthermore, thetemperature of the vaporization chamber was 250 degrees C.

As shown in FIG. 36, the tendency was for the atomization state tobecome less stable the greater was the THF flow rate, and for theatomization state to become more stable the greater was the amount ofcarrier gas. Furthermore, when the carrier gas amount was great, theflow rate of the THF reached an upper limit, and the line L2 shows thisupper limit. For example, at the intersection of the line denoting acarrier gas rate of 400 SCCM and the line L2, the THF flow rate wasabout 1.7 cc/min. In other words, when the carrier gas flow rate was 400SCCM, the flow of THF could not exceed 1.7 cc/min. In a region F1 on thelower side of the line L2 and moreover on the left side of a line L1, itwas possible to perform atomization in a stable manner. However, in aregion F2 on the lower side of the line L2 but on the right side of theline L1, the atomization was unstable.

When for example the flow rate of the liquid mixture of the liquid metalsubstance and the solvent THF flowing in the internal conduit 200 a was0.8 cc/min, it was desirable for the carrier gas rate to be 150 SCCM andthe atomization gas flow rate to be 50 SCCM; and, when the liquidmixture flow rate was 1.2 cc/min, it was desirable for the carrier gasrate to be 250 SCCM and the atomization gas flow rate to be 50 SCCM.

The flow speed of the atomization gas which flows through the gapbetween the orifice member 212 and the internal conduit 200 a is set toa suitable value by adjusting the diametere of the hole in the orificemember 212 corresponding to the external diameter of the internalconduit 200 a of FIG. 33. The end portion of the internal conduit 200 ais centered with respect to the hole in the orifice member 212 by theatomization gas which is flowing through this gap.

Another Example of the Cooling Rod

FIGS. 37 and 38 are sectional views showing first and second variantembodiments of the cooling rod 202. The cooling rod 202B shown in FIG.37 is a single unit which combines the cooling rod 202 and the watercooling block 201 of FIG. 27. This cooling rod 202B comprises a watercooling section 251 and a rod section 252, and is fomed from a substancesuch as copper whose thermal conductivity is high. By contrast with thecooling rod 202 of FIG. 27 which was fixed to the water cooling block201 by a screw structure, by forming them in a unitary construction asin FIG. 37, it becomes possible to enhance the cooling efficiency of therod section 252.

The cooling rod 202C shown in FIG. 38 comprises a further heat pipestructure in addition to the cooling rod 202B of FIG. 37. In detail, inthis cooling rod 202C, an annular chamber 255 is formed from a portionin the vicinity of the cooling water conduit 206 which is provided inthe water cooling section 253 to the tip of the rod section 254. Arefrigerant such as alcohol or the like is enclosed in this chamber 255.This refrigerant enclosed in the chamber 255 is vaporized in the lowerportion of the chamber 255 which is its portion which is at hightemperature, and liquefies in the upper portion of the chamber 255 whichis its portion which is at low temperature. Due to this, the coolingefficiency is enhanced by heat being transferred from the rod section254 to the water cooling section 253 via the refrigerant in addition tothe thermal conduction of the rod section 254, as compared to thecooling rod 202B of FIG. 37. Although with this cooling rod 202C theheat pipe structure was provided by forming the chamber 255 in the rodsection 254, it would also be acceptable to employ a structure in whicha commercially available heat pipe was embedded in the cooling rod 202Bshown in FIG. 37.

Although in FIGS. 27 and 28 the water cooling block 201 and the coolingrod 202 were connected together into one unit by a screw construction,it would also be acceptable for them to be connected together into oneunit by using welding with pressure. In the case that for example such awelding with pressure structure is employed, even if the water coolingblock 201 is made from stainless steel (SUS) which is a different metalfrom copper from which the cooling rod 202 is made, it is possible toenhance the heat transfer efficiency at the interface between these twodifferent types of metal.

Other Examples of the Nozzle Ring

FIGS. 39 and 40 are figures showing first and second variant embodimentsof the nozzle ring 211. The nozzle ring 214 of FIG. 39 is made as atwo-part structure, and comprises a box nut section 214 a and a pressring 214 b. With the nozzle ring shown in FIG. 33, when fixing thenozzle ring 211 to the casing by screwing it on, it may happen that theinconvenience occurs of the orifice member 212 as well rotating togethertherewith. However, in the case of the nozzle ring of the two-partconstruction shown in FIG. 39, even when the box nut section 214 a isbeing screwed on, the orifice member 212 is pressed by the press ring214 b, and thus it is possible to avoid said orifice member 212 turningtogether with the box nut 214 a.

The nozzle ring 215 shown in FIG. 40 is fixed by a screw structure to aflange 216. This flange 216 to which the nozzle ring 215 is fixed isitself fixed to the inner wall surface of the vaporization chamber 21 bya bolt 217. Since heat is conducted from the vaporization chamber 21 tothe nozzle ring 215 via the flange 216, the nozzle ring 215 ismaintained at almost the same high temperature as the vaporizationchamber 21. As a result, it is possible to prevent the development ofnon vaporized residues upon the vaporization surface 215 a. The positionin the axial direction of the nozzle ring 215 can be adjusted byscrewing the nozzle ring 215 into the flange 216. Although in theexample shown in FIG. 40 the nozzle ring 215 and the flange 216 areprovided as separate, it would also be acceptable for them to be formedas a single unit.

It would also be acceptable to coat the surfaces of any of the abovenozzle rings 211, 214, or 215 with PTFE. By doing this, it is made moredifficult for the liquid metal substances to adhere to the nozzle rings211, 214, or 215, and the development of non vaporized residues isfurther reduced. Furthermore, it would also be acceptable to form ablack colored protective film of high chemical resistance such as anoxide layer or the like upon the surface of the nozzle ring 211, 214, or215. This black colored protective layer easily absorbs radiant heatfrom the vaporization chamber 21, so as to bring the temperature of thenozzle ring 211, 214, or 215 to be even closer to the temperature of thevaporization chamber 21.

With the above described vaporizer 2, the metal portions which are incontact with the liquid substances 4A through 4C, such as for examplethe conduits 200 a, 200 b, and 224 and the couplings 22, may be madefrom stainless steel (SUS), but it would also be acceptable for theseparts to be manufactured from a material which has a higher chemicalresistance, such as Ti or a Ti alloy such as TiN or the like.

Another Example of the Vaporizer 2

Next, another example of the vaporizer 2 will be explained. FIG. 41 is asectional view of this other vaporizer 120, while FIG. 42 is a sectionalview of the vaporizer 120 of FIG. 41 taken in a plane shown by thearrows G—G in FIG. 41. In the vaporizer 120 shown in FIG. 41, thestructure of the vaporization chamber 121 is different from that in thevaporizer 2 of FIG. 27, but the structure of the nozzle section 20 whichatomizes the liquid substances 4A through 4C is the same as in the FIG.27 case. The following explanation will focus upon this variantstructure for the vaporization chamber 121. A tubular chamber 122 isformed in the chamber main body 121 a of the vaporization chamber 121 soas to extend in the horizontal direction (the left and right directionin the figure). The nozzle section 20 is fitted so as to inject atomizedgas downwards in the vertical direction into the tubular chamber 122. Aside cover (flange) 121 b of the vaporization chamber 121 is formed soas to be detachable and attachable with respect to the chamber main body121 a. For example, when it is desired to perform cleaning of theinterior of the vaporization chamber 121, the side cover 121 b isremoved, and the tubular chamber 122 is exposed to the atmosphere andcleaning is performed.

The liquid substances 4A through 4C which have been atomized by thenozzle section 20 of FIG. 41 are spouted in the direction of the surfaceof the tubular chamber 22 which opposes the end portion of theatomization section, and as shown in FIG. 42 flow back upwards along theinner peripheral surface of the tubular chamber 122 as shown by thearrows R1. Heaters h1 through h9 are provided in the vaporizationchamber 121, and temperature control is performed so as to keep higherthan the vaporization temperature. Due to this, the liquid substances 4Athrough 4C, which already are in the form of mist, are vaporized whileflowing around the inner peripheral chamber surface in this manner, andare expelled along with the carrier gas from the exhaust orifice 129towards the CVD reactor.

The heaters h1 through h9 are provided in the vaporization chamber mainbody 121 a and the side cover 121 b. Three of the heaters h1 through h3are controlled by a temperature adjustment device 132 based upon thetemperature which is detected by a temperature sensor 130. The other sixheaters h4 through h9 are controlled by another temperature adjustmentdevice 133 based upon the temperature detected by a temperature sensor131. The entire inner peripheral surface of the tubular chamber 122functions as a vaporization surface. In particular, since as shown inFIGS. 41 and 42 the liquid substances 4A through 4C are spouted from thenozzle section 20 almost in the vertically downwards direction, thesurface S11 shown in FIG. 42 constitutes the main vaporization surface.Due to this, when the amount to be vaporized (in other words, the flowrate of the liquid substances 4A through 4C) is large, the temperatureof the vaporization surface S11 drops below the vaporization temperatureand it can easily happen that non vaporized residues may accumulate uponthis vaporization surface S11.

In this connection, with the vaporizer 120, the heaters h1 through h3which are in the vicinity of this main vaporization surface S11 and theother heaters h4 through h9 are controlled by the two differenttemperature adjustment devices 132 and 133, so as to ensure that thetemperature of said main vaporization surface S11 is maintained at themost suitable temperature for vaporization. In other words, the supplyof power to the heaters h1 through h3 to generate heat energy isadjusted according to the natures of the liquid substances 4A through 4Cwhich are to be vaporized and according to their flow rates, so as tomaintain the temperature of the main vaporization surface S11 at themost suitable temperature for vaporization. As a result, it is possibleto reduce the generation of non vaporized residues upon the vaporizationsurface S11. For example, if the amount of heating energy is increased,and the temperature of the vaporization surface S11 is set to be higherthan the temperature of the vaporization chamber 121, this can be veryeffective in the case when the temperature of pyrolysis (thermaldecomposition) of the liquid substances 4A through 4C is quite close totheir vaporization temperature.

Although the vaporization chamber 121 is generally made from stainlesssteel (SUS), in this case, there have been problems of chemicalreactions taking place between the wall surface of the tubular chamberwhich functions as the vaporization surface, and the liquid substances4A through 4C. With the vaporizer 120, in order to prevent this type ofchemical reaction taking place between the wall surface and the liquidsubstances 4A through 4C, the wall surface is coated with a film madefrom a material such as CVD. As a result, the wall surface of thetubular chamber 122 is protected by this film coating, and it ispossible to prevent the occurrence of chemical reactions between saidwall surface and the liquid substances 4A through 4C. For example, inthe case of a vaporizer which is used in a CVD device which forms a BSTfilm (a film of BaSrTi oxide), a similar BST film is used as the coatingfor the wall surface. As such a film, instead of BST, it would also bepossible to utilize a dielectric film such as a PZT film (a PbZrTifilm), a STO film (SrTiO₂), a TiO₂ film, a SBT film (a SrBiTa oxidefilm) or the like, or an oxide superconducting film or the like.

With the above described vaporizer 120, the construction is such thatthe various types of liquid substance 4A through 4C are mixed together,and the resultant liquid mixture is sprayed into the vaporizationchamber 121 and atomized, so as to be vaporized therein. However, if asshown in FIG. 43 the pyrolysis temperatures and the vaporizationtemperatures of the various liquid substances 4A through 4C areradically different from one another, problems can arise when the mixedliquid consisting of all the liquid substances 4A through 4C isvaporized upon the single vaporization surface S11, as in the case ofthe vaporizer 120 described above.

In the example shown in FIG. 43, the liquid substances 4A and 4B havealmost the same pyrolysis temperatures and vaporization temperatures,while the liquid substance 4C has a much higher pyrolysis temperatureand vaporization temperature. The vaporization temperature of a materialis defined as the minimum temperature at which vaporization can beperformed, while the pyrolysis temperature of a material is defined asthe minimum temperature at which pyrolysis occurs. It is necessary tomaintain the temperature of a vaporization surface between thevaporization temperature and the pyrolysis temperature. If the pyrolysistemperatures T_(da), T_(db), and T_(dc) and the vaporizationtemperatures T_(va), T_(vb), and T_(vc) of the liquid substances 4Athrough 4C are as shown in FIG. 43, the temperature of the vaporizationsurface S11 should be set to and maintained at a temperature like thetemperature T1 shown in FIG. 43 When this temperature has been set toT1, for the substance 4C, vaporization is being performed at atemperature at which vaporization is only marginally possible, while,for the liquid substances 4A and 4B, vaporization is being performed ata temperature at which pyrolysis is almost occurring. As a result, thetemperature control of the vaporization surface S11 becomes an extremelydemanding task, and the problem arises that any variation of thetemperature will cause the vaporization conditions to becomeunacceptable.

In this connection, in the vaporizer 40 of FIG. 44, the mixture of thetwo liquid substances 4A and 4B, and the liquid substance 4C, areindividually vaporized upon two different vaporization surfaces S21 andS22 which are temperature controlled independently. Thus, in thevaporizer 40 of FIG. 44, two nozzle sections 41 and 42 are provided inthe vaporization chamber 43. The liquid substance 4C is atomized by thenozzle section 41, while the liquid substances 4A and 4B are mixedtogether and the resultant mixture is atomized by the nozzle section 42.The liquid substance 4C which has been atomized by the nozzle section 41is spouted in the vertically downwards direction towards thevaporization surface S21 in the tubular chamber 45, and is mainlyvaporized by this vaporization surface S21. On the other hand, themixture of the liquid substances 4A and 4B which has been atomized bythe nozzle section 42 is spouted in the vertically downwards directiontowards the vaporization surface S22 in the tubular chamber 45, and ismainly vaporized by this vaporization surface S22.

Heaters h11 through h17 are provided in the vaporization chamber 43 forheating it. Temperature control of the chamber 43 as a whole isperformed by a temperature adjustment device 46, based upon thetemperature detected by a temperature sensor 44, by controlling theenergy supplied to the heaters h15 through h17 and thereby the heatenergy emitted by them. Temperature control of the vaporization surfaceS21 is performed by a temperature adjustment device 48, based upon thetemperature detected by a temperature sensor 47, by controlling theenergy supplied to the heaters h11 and h12 and thereby the heat energyemitted by them. And temperature control of the vaporization surface S22is performed by a temperature adjustment device 50, based upon thetemperature detected by a temperature sensor 49, by controlling theenergy supplied to the heaters h13 and h14 and thereby the heat energyemitted by them.

If for example the qualities of the liquid substances 4A through 4C areas shown in FIG. 43, the temperatures of the vaporization surfaces S21and S22 are individually controlled to be equal to the temperatures T11and T12, which are substantially different from one another. Due tothis, it is possible to perform vaporization of all of the liquidsubstances 4A through 4C at the most suitable vaporization temperaturesin view of their particular characteristics. Furthermore, since twonozzle sections are provided, it is possible to anticipate a greateroverall rate of vaporization per unit time, by contrast with the case ofa vaporizer such as that shown in FIG. 41 in which only one nozzlesection is provided.

Moreover, it would be possible to perform vaporization of all of theliquid substances 4A through 4C at the most suitable vaporizationtemperatures in the prior art type vaporizer case as well, if twoseparate vaporizers were to be provided, in one of which the mixture ofthe liquid substances 4A and 4B was vaporized, while the liquidsubstance 4C was vaporized in the other. However, along with increasingthe size of the system as a whole, such an expedient would also greatlyincrease its cost. By contrast, it is possible remarkably to restrainincrease in the size and cost of the vaporizer system by using thevaporizer 40 of the type described above.

Since in the example shown in FIG. 43 the characteristics with regard tovaporization and pyrolysis of two of the liquid substances 4A and 4Bwere very similar, they were mixed together and the resultant mixturewas injected through a single nozzle section 41 and thereby was atomizedand vaporized; but, if the characteristics of all the three liquidsubstances 4A, 4B, and 4C differed markedly from one another, it wouldalso be possible, as an alternative, to provide each of these liquidsubstances 4A through 4C with its own dedicated nozzle section.

In another vaporizer variant shown in FIG. 45, a tongue 62 is providedupon the inner side of the side cover 61. FIG. 46 is a sectional view ofthe vaporizer 60 of FIG. 45 taken in a plane shown by the arrows H—H inFIG. 45, and shows a cross section of the tongue 62, which extends inthe horizontal direction and opposes the nozzle section 20 in thevertical direction. Heaters h21 and h22 and a temperature sensor 63 areprovided in the tongue 62. These heaters h21 and h22 and the temperaturesensor 63 are connected to a temperature adjustment device 65. Theliquid substance 64 which is spouted towards the tongue 62 is vaporizedby the vaporization surface S30 of the tongue 62. The heaters h21 andh22 are controlled, based upon the temperature which is detected by thetemperature sensor 63, so as to keep the temperature of the tongue 62 ata somewhat higher temperature than that of the chamber main body 121 a.On the other hand, the amounts of energy supplied to the heaters h1through h9, and thereby the amounts of heat energy which they evolve,are controlled by a temperature adjustment device 66 based upon thetemperature which is detected by a temperature sensor 131 which isprovided in the chamber main body 121 a.

In the case of this vaporizer 60 as well, it is possible to obtain thesame beneficial results as in the case of the vaporizer 120 describedabove, since the construction makes it possible to adjust thetemperature of the vaporization surface S30 separately from thetemperature of the chamber main body 121 a. Furthermore, since in thisvaporizer 60 the tongue 62 is provided as a separate unit and itstemperature can be independently controlled, therefore this vaporizer 60differs from the previously described vaporizer 120 in that a portion ofthe vaporization chamber 121 is independently temperature controlled,and accordingly the temperature control characteristics are improved.

Yet further, when cleaning the vaporization chamber 60, since the nonvaporized components which are inevitably produced by a substantialperiod of vaporization chiefly adhere to the upper side of the tongue62, therefore it is possible to remove the side cover 61 to cleanse thetongue 62 separately. Due to this it is possible to perform theoperation of cleaning simply, and also the reliability of the cleaningoperation is enhanced.

In another vaporizer variant shown in FIG. 47 two nozzle sections 41 and42 are provided, in the same manner as in the vaporizer 40 which wasshown in FIG. 44. A tubular chamber 77 is formed in the chamber mainbody 74 of the vaporization chamber 73, and extends in the horizontaldirection in the figure. At the left and right ends of this tubularchamber 77 there are provided covers (flanges) 75 and 76 which can beremoved and re-attached. Tongues 71 and 72 are formed upon these covers75 and 76. The temperature of the vaporization chamber 73 is maintainedat a specified temperature by heaters h31 through h36, a temperaturesensor 77 and a temperature adjustment device 78.

The tongue 71 is provided at a position upon the cover 75 which opposesthe nozzle section 41, and the surface S31 of this tongue 71 functionsas a vaporization surface for the liquid substance 4C. A heater h37 anda temperature sensor 79 are provided in this tongue 71. The heater h37is controlled by a temperature adjustment device 80, based upon thetemperature sensed by the temperature sensor 79, so as to maintain thetemperature of the tongue 71 at the temperature T11 shown in FIG. 43.Similarly, the tongue 72 is provided at a position upon the cover 76which opposes the nozzle section 42, and the surface S32 of this tongue72 functions as a vaporization surface for the mixture of the liquidsubstances 4A and 4B. A heater h38 and a temperature sensor 81 areprovided in this tongue 71. The heater h38 is controlled by atemperature adjustment device 82, based upon the temperature sensed bythe temperature sensor 81, so as to maintain the temperature of thetongue 72 at the temperature T12 shown in FIG. 43.

In this vaporizer 70 shown in FIG. 47 as well, in the same manner as inthe vaporizer 40 shown in FIG. 44, there are provided two vaporizationsurfaces S31 and S32 whose temperatures are different and are setindividually in correspondence to the characteristics of the liquidsubstances 4A through 4C which are to be vaporized. And, since thetemperatures of these two vaporization surfaces S31 and S32 arecontrolled independently, the same benefits are obtained as in the caseof the vaporizer 40, described above. Moreover, since in this vaporizer70 the two separate tongues 71 and 72 are provided and the vaporizationsurfaces S31 and S32 are formed upon the upper surfaces of these tongues71 and 72, therefore the temperature controllability for these twovaporization surfaces S31 and S32 is even more improved, as compared tothe case with the vaporizer 40 described above.

Explanation of the Vaporization Performance Appraisal Method

Next, the method according to this preferred embodiment of the presentinvention for appraising the vaporization performance of the vaporizerwill be explained. The vaporization performance of the vaporizer isappraised according to what percent of the liquid substance which issupplied to the vaporizer is vaporized. This can be determined accordingto the difference between the amount of supply and the amount of thenon-vaporized component within the vaporizer. FIG. 48 is a figureshowing a procedure for measuring vaporization performance, and thisprocedure will be explained in the following in terms of the case inwhich Ba, Sr and Ti are used as the substances to be vaporized.

In the step 1 of FIG. 48, predetermined amount of liquid substances arevaporized by the vaporizer. Next, in the sampling process of step 2, thenon-vaporized components which have adhered over the entire wall surfaceof the vaporization chamber including the vaporization surface areremoved by the use of ethyl alcohol or the like. For example, a cloth ofabout 0.1 to 0.3 g in weight is wetted with ethyl alcohol, and thenon-vaporized components which have adhered to the wall surfaces arewiped off with this cloth. In an organic material decomposition “A”process of step 3, the cloth, after it has thus been used for wiping offthe wall surfaces, is soaked with a mixture liquid consisting of 2 ml ofhydrochloric acid, 0.5 ml of hydrogen peroxide and 1 ml of pure water,which is then heated for 1.5 hours at a temperature of 150 degrees C.,so that the organic material which has adhered to the cloth isdecomposed. In an organic material decomposition “B” process of step 4,a further 1 ml of hydrochloric acid, 0.5 ml of hydrogen peroxide and 1ml of pure water are added to the solution of step 3, and is heated fora further 1.5 hours at a temperature of 150 degrees C.

In a boiling and concentration process of step 5, a further 1 ml of purewater is added, and the solution is heated for a further 0.5 hours at atemperature of 150 degrees C. In a filtering and constant volume processof FIG. 6, after the solution of step 5 has been filtered, 1 ml ofhydrochloric acid is added, and the volume is adjusted to 20 to 100 ml.In a step 7, quantitative analysis for each of the elements Ba, Sr, andTi is performed by an analysis device which uses ICP (inductivelycoupled plasma), and the amounts of the non-vaporized components arecalculated. When performing this quantitative analysis, working curvesbased upon the ICP analysis which has been performed on the testmaterials like those shown in FIG. 49 are used and the amounts ofnonvaporized components are calculated by comparison with these workingcurves. In a step 8, the vaporization ratio is calculated from theamounts of the liquid substances which were used for vaporization andfrom the amounts of nonvaporized components which were calculated in thestep 7. With the appraisal method shown in FIG. 48, it becomes possibleto appraise the vaporization performance of the vaporizer accurately,because the non-vaporized components which adhere to the wall surfaceswithin the vaporizer are actually subjected to quantitative analysis.

1. A vaporizer that supplies a vaporized liquid substance to a CVD filmdeposition device, comprising: an atomization section which sprays agas/liquid mixture substance consisting of a mixture of a liquidsubstance which comprises a liquid organometal or an organometalsolution and a carrier gas, from an end portion of a transfer conduit;and a vaporization section which vaporizes said sprayed liquidsubstance, wherein: said transfer conduit is made as a double conduitcomprising an internal conduit in which the liquid substance istransferred as a gas/liquid two phase flow and an external conduit intowhich said internal conduit is inserted keeping a space therebetween andwhich is provided in order to transfer gas for atomization, the gas foratomization flowing into a first end of the external conduit, throughthe space, and exiting a second end of the external conduit remote fromthe first end; an orifice member provided nearer to said second end thanto said first end, in which an aperture portion is formed into whichsaid internal conduit is inserted keeping a gap therebetween and the gasfor atomization which has been transferred by said external conduit isspouted into said vaporization section through said gap, is provided atan end portion of said internal conduit; the vaporizer further comprisesa nozzle ring which is provided at a tip of said atomization section ina vicinity of said end portion of said internal conduit, and upon whicha vaporization surface is formed which prevents the liquid substancewhich has been vaporized from re-condensing; and a cooling member isprovided around said transfer conduit in contact with said externalconduit and extends to around the end portion of said transfer conduit.2. A vaporizer according to claim 1, wherein said orifice member is madefrom PEEK (polyether ether ketone) and is sandwiched between said nozzlering and a tip of said external conduit, and a seal member made fromPTFE (polytetrafluoroethylene) is disposed between said orifice memberand said tip of said external conduit.
 3. A vaporizer according to claim2, wherein said nozzle ring comprises a first member which is engagedwith the tip of said atomization section by screwing, and a secondmember which is provided separately from said first member and issandwiched between said orifice member and said first member.
 4. Avaporizer that supplies a vaporized liquid substance to a CVD filmdeposition device, comprising: an atomization section which sprays agas/liquid mixture substance consisting of a mixture of a liquidsubstance which comprises a liquid organometal or an organometalsolution and a carrier gas, from an end portion of a transfer conduit;and a vaporization section which vaporizes said sprayed liquidsubstance, wherein: said transfer conduit is made as a double conduitcomprising an internal conduit in which the liquid substance istransferred as a gas/liquid two phase flow and an external conduit intowhich said internal conduit is inserted keeping a space therebetween andwhich transfers gas for atomization; an orifice member, in which anaperture portion is fonned into which said internal conduit is insertedkeeping a gap therebetween and the gas for atomization which has beentransferred by said external conduit is spouted into said vaporizationsection through said gap, is provided at an end portion of said internalconduit; and the vaporizer further comprises a nozzle ring which isfixed to said vaporization section in a vicinity of said end portion ofsaid internal conduit, and upon which a vaporization surface is formedwhich prevents the liquid substance which has been vaporized fromre-condensing, wherein said orifice member is made from PEEK (polyetherether ketone) and is sandwiched between said nozzle ring and a tip ofsaid external conduit, and a seal member made from PTFE(polytetrafluoroethylene) is disposed between said orifice member andsaid tip of said external conduit.
 5. A vaporizer according to claim 1,further comprising: as a coupling which fixes said internal conduit tosaid atomization section, a gasket type seal coupling which comprises ametal gasket and a pair of coupling members which are provided so as tosandwich said metal gasket between them, wherein one of said pair ofcoupling members is fixed to said atomization section while the other ofsaid pair of coupling members is fixed to said internal conduit, and anamount of projection of the end portion of said internal conduit fromsaid orifice member can be adjusted by adjusting an amount of screwingin an axial direction of said gasket type seal coupling.
 6. A vaporizeraccording to claim 1, wherein said nozzle ring is kept at a hightemperature so as to prevent the liquid substance which has beenvaporized from re-condensing.
 7. A vaporizer that supplies a vaporizedliquid substance to a CVD film deposition device, comprising: anatomization section which sprays a gas/liquid mixture substanceconsisting of a mixture of a liquid substance which comprises a liquidorganometal or an organometal solution and a carrier gas, from an endportion of a transfer conduit; and a vaporization section whichvaporizes said sprayed liquid substance, wherein: said transfer conduitis made as a double conduit comprising an internal conduit in which theliquid substance is transferred as a gas/liquid two phase flow and anexternal conduit into which said internal conduit is inserted keeping aspace therebetween and which transfers gas for atomization; and anorifice member, in which an aperture portion is formed into which saidinternal conduit is inserted keeping a gap therebetween and the gas foratomization which has been transferred by said external conduit isspouted into said vaporization section through said gap, is provided atan end portion of said internal conduit, wherein said vaporizer furthercomprises: as a coupling which fixes said internal conduit to saidatomization section, a gasket type seal coupling which comprises a metalgasket and a pair of coupling members which are provided so as tosandwich said metal gasket between them, wherein one of said pair ofcoupling members is fixed to said atomization section while the other ofsaid pair of coupling members is fixed to said internal conduit, and anamount of projection of the end portion of said internal conduit fromsaid orifice member can be adjusted by adjusting an amount of screwingin an axial direction of said gasket type seal coupling.
 8. A vaporizeraccording to claim 1, wherein the gas for atomization enters thevaporizer and meets a junction of a first path, which leads to theorifice member, and a second path, which leads to a terminating end, andthe cooling member is provided around the first path.
 9. A vaporizeraccording to claim 1, wherein the cooling member and the externalconduit are members different from each other.